title: Ionic strength-dependent conformations of a ubiquitin-like small archaeal modifier protein (SAMP2) from Haloferax volcanii.
abstract: Ubiquitin-like proteins play important roles in diverse biological processes. In this study, we present an unexpected finding that a ubiquitin-like small archaeal modifier protein (SAMP2) from Haloferax volcanii adopts two distinct states under low ionic condition. One of these is similar to the β-grasp structure conserved in ubiquitin-like proteins from eukaryotes; the other is disordered, like prokaryotic ubiquitin-like protein, Pup. Furthermore, our study reveals that the conformation of SAMP2 is dependent on ionic strength. With the increase of ion concentration, SAMP2 undergoes a conformational conversion from disorder to order, indicating that the ordered conformation is the functional form of SAMP2 under the physiological condition of H. volcanii.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
authors.forename: Shanhui
authors.initials: S
authors.lastname: Liao
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Kai
authors.initials: K
authors.lastname: Fan
authors.forename: Kaiqin
authors.initials: K
authors.lastname: Ye
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.forename: Jiahai
authors.initials: J
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Tu
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry*; D019622:Haloferax volcanii / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009994:Osmolar Concentration; D010802:Phylogeny; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D019843:Archaeal Proteins; D025801:Ubiquitin